#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

int main()
{
	int a = 0, b = 0, c = 0;
	while(scanf("%d %d %d", &a, &b, &c)!=EOF)
	{
		if (a + b > c && a - b < c)
		{
			if ((a == b) &&(a==c))
				printf("Equilateral triangle!\n");
			else if ((a == b&&a!=c)||(a==c&&a!=b)||(b==c&&b!=a))
				printf("Isosceles triangle!\n");
			else
				printf("Ordinary triangle!\n");
		}
		else
			printf("Not a triangle!\n");
	}
	return 0;
}